A plurality of horizontal I-beams supported by vertical columns has been widely used to support horizontal runs of plastic pipe, as illustrated in FIG. 1. As shown in FIG. 2, the conventional manner for securing plastic pipe to an I-beam positioned transverse to the longitudinal axis of the pipe has been to drill a pair of holes in a flange of the I-beam to receive the threaded ends of a U-bolt, place an arcuate wear plate on the surface of the flange between the holes, lay the pipe on the wear plate, insert the threaded ends of the U-bolt through the holes, and wind nuts up the threaded ends until the U-bolt firmly secures the pipe to the beam. The requirement for drilling holes in I-beams made this method relatively slow, awkward, and labor-intensive.
Manasek, U.S. Pat. No. 2,562,562, disclosed a pipe and conduit supporting clamp, comprising two laterally spaced C-shaped clamp bodies transversely connected together at adjacent ends by an arcuate portion. A screw was threaded through the middle of the arcuate portion. When the pipe was placed on a top surface of a flange of a structural member, the clamp bodies engaged a bottom surface of the flange, the arcuate portion partially surrounded the pipe, and advancement of the screw urged the pipe against the top surface of the flange. By inverting the clamp, a pipe could likewise be attached to a bottom surface of a flange of a structural member. Although Manasek's clamp eliminated the need to drill holes in the flanges of structural steel members, Manasek's clamp still required use of wear plates for plastic pipe.
Stange, German Patent No. DE 31 10716, disclosed first and second pairs of clamping jaws. Each of the jaws had a clamp groove. The jaws of the first pair engaged a first flange of an I-beam in spaced relation, and the jaws of the second, oppositely disposed pair engaged an opposite flange of the beam in similar spaced relation. One jaw of each of the first pair of clamping jaws also had a shoulder with a screw hole for receiving a threaded end of a U-bolt. Tensioning screws connected the oppositely disposed jaws, whereby the jaws could be reversibly secured to the beam. Like Manasek's, Stange's device also eliminated the need to drill holes in the flanges of structural steel members, but still required the use of wear plates for plastic pipe.
Madej, U.S. Pat. No. 4,397,437, disclosed an I-beam clamp comprising a saddle-shaped member for urging a conduit supported on a U-bolt into engagement with an I-beam by the threaded engagement of encapsulated nuts on the threads of the U-bolt. Although Madej's clamp did not require the drilling of holes in an I-beam flange, it was designed for attachment to one flange only of an I-beam, and thus lacked the mechanical stability afforded by devices that simultaneously engage both of the opposite flanges of a beam. Moreover, when used with plastic pipe, Madej's clamp also required insertion of a wear plate between the pipe and the beam.